Slapd sometimes stucks: slapd shutdown: waiting for N operations/tasks to finish

[Покотиленко Костик <casper@meteor.dp.ua>]

Hi,

In our 1 Master - several slaves environment master slapd sometimes
stucks in such condition that it takes minutes to get replay to simple
queries with no visible resource consumption on both: the slapd process
itself and the linux it is running on.

Restarting slapd helps for several days. Today I have not been able to
restart it without kill -9 because of:

slapd shutdown: waiting for 12 operations/tasks to finish

Waited 5 minutes with no luck, kill -9, start.

slapd: 2.4.28
OS: Ubuntu 12.04.2 LTS

I'm Ok with "try latest version", but it would be nice to have some
pointers (maybe bug in this version or error in configuration).

The server is running for 6+ month with no problems. The stucks first
appeared 2 weeks ago after changing ACLs to use group.exact instead of
set which came deadly slow.